package demo;

/**
 * 环形链表
 */
class Solution9 {
	public boolean hasCycle(ListNode head) {
		ListNode slow = head;
		ListNode fast = head;
		while (fast != null && fast.next != null) {
			slow = slow.next;
			fast = fast.next.next;
			if (slow == fast) {
				return true;
			}
		}

		return false;
	}
}

